The invention relates to a plastic wheel assembly particularly well suited for utility vehicles, more particularly for use on golf cars.
The conventional golf car is provided with metallic rims. The rim includes a pair of annular flanges adapted to engage the bead of a pneumatic tire, and a rim base interposed between the flanges. A disk extends radially inwardly from the base and is adapted to fit over the studs of the golf car hub.
The disk is approximately axially centered between the bead flanges. This position enables the disk to support the vehicle load with minimal eccentric or bending forces. This central location of the disk means that the vehicle hub is encased within the rim assembly.
The hub of a golf car includes a drum brake system, the inner surface of the hub being a drum brake surface. The hub under severe braking service can reach temperatures in excess of 400.degree. F. and the hub being of cast iron tends to hold temperatures for relatively long periods of time.
These friction-generated high temperatures are not a problem for metal rims, but for a thermoplastic wheel such temperatures are design limiting. The in- service temperatures are so high that most engineering plastics cannot be used as these materials melt or lose physical properties at these operating temperatures.
The present invention overcomes the high heat problems associated with the vehicle hub while at the same time permitting the use of rather conventional thermoplastic resins.
The present invention is easily adapted to current vehicle wheel designs and is fully interchangeable with the prior art metal wheel assemblies.